Download the latest Flash Player for Firefox here:
You may have to download it with any browser that ignores the xpi extension - firefox tries to install it right away!
Rename the xpi file to a zip file and extract the files flashplayer.xpt and NPSWF32.dll to your Firefox/plugins folder!
After restarting firefox you got the latest version of Flash Player without any nagging Adobe DLM or whatever... :)
[Update: The version of flash player in the link above is quite old...
Using the following link also works:
(for non active x browsers)
Just run the exe and follow the steps...]